shift8
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Posts posted by shift8
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I am not here to disprove anything you have said. But I do know for a fact, this part of your statement was incorrect. I have played way to much to know that the 85 has no issue at all penetrating a Tigers armor. No matter what direction and at long distances, not just short ranges.
As for your other request. I know of too many actual accounts from the period that will disagree with what you think a 76 round is going to penetrate at the ranges you are hoping for. Since a Sherman 75 as I recall was just a fraction better as to performance. I am sure there is plenty of evidence that there was not a lot of chance of a full penetration unless the distances were very close. but for sure not at distances 500-1000 meters.
I just went and double checked the 85mm gun in CMRT, since I did those tests separately and a long time ago. I got the results I expected. Just like the 76mm gun on the Sherman, most rounds are PP's or Just hits. about 1/3rd of all hits are penetrations, which is very much like the American 76 in CMBN. Test was at 600m.
As for said reports, its hard to judge anecdotal evidence. Just like the stuff I mentioned, alot of vehicles that were not Tigers were reported as such. There is no reason what so ever that the 76mm and 85mm guns should not penetrate the Tigers front at normal combat ranges, unless the angle of impact is very high. Also, the 76mm and 75mm guns are Far more than fraction different in performance. It is night and day. The 76mm gun makes it through 93mm at 30 @ 500m, and the 75mm only makes it though 66. The difference is huge.
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After considerable testing in CMBN, I have determined (as many here already are aware) that the Tiger deflects almost all 76mm hits from the front at ranges well within the penetration zone for the 76mm gun at low obliquity at ranges of 500 to 1000m. In my estimation, there seems to be no reason what-so-ever that the 76mm gun should not be able to reliably penetrate the Tigers frontal armor at reasonable angles under 1000m. At the very least under 800m. What exactly is battlefronts reason for this?
I personally suspect that this is intended to be the shatter gap, a effect that I personally think is nonsense. At the very least, it is being overdone.
According to Rexfords book( battlefront having already made it clear that they used this author for advice) the shatter gap theory is predicated on a few oddball tidbits thrown together to prove an effect whose original source was unfounded in the first place.
Rexford states that origin for historical belief in this problem comes from Bailey's accounts from Tiger engagements in Normandy. This entire source can be discarded out right since there were no Tiger tanks fighting the Americans in Normandy, making this a clear example of American tank crews presuming every vehicles was a Tiger. In other words, the origin for this is nonsense.
He then goes on to state that Isigny tests on the Panther mantlet, presuming that the reason 76mm rounds could only penetrate at 200m was due to shatter gap. This is as massive stretch, as we dont necessarily know what parts of the mantlet were struck, or at what angle. IE: if they hit the mantley square, they should go through, but striking the upper or lower parts would be alot harder to penetrate. Essentially, this is case of making specific assumptions about the conditions and results of a test to prove a phenomenon. Completely silly.
He also shows the 3inch gun tests and makes alot of assumptions as to what they actually show. Said tests make no mention of shatter gap failure, but he assumes that when failures did occur inside the ratios he concocted up, that they occurred due to shatter gap.
However the real issue here is that all of this witchcraft is in direct contention with the actual data.
We already know from US gun tests that more than 50% of the time they were capable of penetrating the amount of armor listed in the charts. Those rounds were standard M62 projectiles with the same 59 Rockwell that he claims would have caused this this issue on American and other nations rounds.
Shoeburyness tests even showed 76mm APCBC making it though 100mm armor at as much as 30 degrees at 500m.
In other words, even if shatter gap was real, if did not prevent the rounds from performing according to the American penetration tables, which presume a 50% success rate like most other nations tables. Clearly there is room for success above this rate was well, as the shoeburyness tests show. This issue would also affect the 85mm gun on T-34, which should also be able to penetrate the Tiger in CMRT, but cannot......despite there being tests, complete with photographs, of this being the case.
So what is the deal here? And how can we get this changed?
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Don't have the book (£365.98!) to hand but does it specify if that result was found out from combat or subsequent allied testing on say captured Tiggers conducted in France after the battles in Normandy moved on.
http://www.amazon.co.uk/Faint-Praise-American-Destroyers-During/dp/0208020063
There were ZERO, I say again:--ZERO-Tigers on the American sector in Normandy. Any accounts Faint Praise uses are just good examples of Americans reporting everything as a Tiger. From the descriptions in Rexfords own book, they appear to combat accounts. I have never seen any 1944 tests on Tigers done by the United States. The tests on German tanks done after and during the battle are well known, specifically the isigny tests, which involved no Tigers. On the subject of those tests, they did test the 76mm gun on a 100mm armor plate at 30 degrees, and it penetrated just fine---a fact Rexford dismisses in his book. In CMx1, the Shatter gap for the 76mm gun was fairly rare, but in CMx2 it is all over the place. Even German tests claim the 76mm gun could Kill the Tiger from 400-600M.
Outside of Rexford and Bailey, I havent been able to find anyone else claiming "Shatter Gap" was a thing aside from people quoting either Rexford or Bailey. Anything used in Baileys book should be taken with a large grain of salt in particular----since it is one of those "The shermans are death trap, oh my, how stupid the Army was to not have 90mm guns," sort of narratives.
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The following presents the latest research findings regarding the shatter failure of U.S. 76mm APCBC against heavy German armor (80mm and thicker):
SHATTER GAP FAILURE OF U.S. 3” CHEVROLET APCBC
Firing trials and combat reports from WW II suggest that the Chevrolet 3” APCBC round was susceptible to shatter gap failure, where hits which should have penetrated resulted in defeats. The following summarizes all of the research conducted by this writer on the subject of U.S. 76mm APCBC shatter gap and refines past estimates.
1. Report in Faint Praise book that U.S. 76mm penetrated front of Tiger at 50 yards in France but failed at further ranges
2. U.S. firing trials against captured Panthers in France (First U.S. Army, July 1944) where penetration range against Panther mantlet is limited to 200 yards (183m)
3. U.S. Navy firing tests against American 3.8” and 3” plate result in two distinct velocities for 50% success separated by a wide band of failure velocities with extensive projectile damage
Analysis of the above information results in the following shatter gap characteristics:
3.82” at 20 deg, U.S. Navy, 1.124 shatter gap penetration ratio
3.84” at 30 deg, U.S. Navy, 1.125
3.00” at 20 deg, U.S. Navy, none (no shatter gap exhibited)
3.00” at 30 deg, U.S. Navy, 1.229
3.00” at 40 deg, U.S. Navy, 1.193
102mm at 10 deg, Faint Praise, 1.210
100mm cast at 0 deg, U.S. First Army, 1.323
100mm cast at 10 deg, U.S. First Army, 1.284
100mm cast at 20 deg, U.S. First Army, 1.160
Notes:
1. The Shatter Gap Penetration Ratio is the ratio of the higher penetration figure for 50% success divided by the lower limit (based on computed effective armor resistance), where the figures in between would result in a high failure probability due to projectile shatter
2. The First Army tests against the Panther mantlet did not indicate or suggest an impact angle, so three possible angles are analyzed where the lower angles may be more likely
Applying the above results to the Tiger effective armor resistances results in the following ranges for potential shatter gap failure by Chevrolet 76mm APCBC (50% penetration probability at listed ranges, zero percentage in between and normal penetration probabilities outside the range):
102mm plate hit at 10 degrees, 46m to 1050m
102mm plate hit at 20 degrees, 100m to 750m
102mm plate hit at 30 degrees, 25m
84.5mm side armor resistance at 20 degrees, no shatter gap possibility
84.5mm side armor resistance at 30 degrees, 0m to 1100m
84.5mm side armor resistance at 40 degrees, no shatter gap possibility, no 50% intact penetration limit
For the Panther mantlet, the upper and lower penetration ranges appear to occur at 183mm and 1500m.
Research by Miles Krogfus has found that the Chevrolet M62 3” round was susceptible to a variety of problems due to a relatively rapid decrease in hardness from nose to main body, which could lead to bulging out of the projectile shoulder after impact. There were two other manufacturers of U.S. 76mm APCBC and the other makers used a slower variation than Chevrolet for the hardness from nose to main body.
Id love to know what Tiger he supposedly engaged, given that there were no Tigers on the American front in france....
Also, those mantle hits mean nothing. For all we know, the penetration might have been limited due to the failure rounds hitting the upper or lower sections of the mantlet.
As for the Navy tests: Id like to see those....and see if they make any mention of shatter gap. Funny how this problem never came up in the original testing of these guns.
What is more, with this being only one of the 2 manufactures, you wouldnt expect it to happen 75% of the time like it does now
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shift8,
I have CMBB, but I can't play it, since I no longer have a Motorola chip in my iMac. I took the data from the CMBB Strategy Guide, the CMBB bible, if you will. Perhaps a patch subsequently changed the F-34 penetration numbers. I don't recall where I got the Tiger 1 UH figure, but it's possible I conflated it or that a typing problem I sometimes have (fingers don't listen to brain) may've caused the mistake. You seem to flatly contradict yourself when it comes to F-34 penetration performance.
CMBB numbers for 100, 500 and 100 meters APC 93, 73, 63 APCR 133, 96, 62
You then cite actual Russian figures of 88, 69 and 60 for APC, which are pretty close to the CMBB numbers. Either set of APC values will pierce the 80 mm on the StuG III/F's UH. Next, you say
"76mm APC did not penetrate the 80mm of armor on Stugs or Pz4s: in game, theoretically, or IRL. It doesnt even come close. Even the German figure you posted completely agree with that."
Is this some sort of New Math? If we use the German numbers for APC, the F-34 can barely penetrate (by 1 mm) the armor at 100 meters, but using the CMBB numbers you provided, absolutely will penetrate it at 100 meters (93 > 80). In reviewing the penetration curve chart I linked to, I see my brain got a bit overloaded from too much going on visually, causing me to read the wrong line. The Russian original is much easier to follow, since each curve is directly labeled. I should've said Russian data show the F-34 will defeat the Tiger 1's 80 mm thick side armor at 100 meters. Obviously, this means the projectile is APC. If the F-34 can defeat the 80 mm thick vertical UH side armor on a Tiger 1 at 100 meters, how is it, then, it can't defeat the self same 80 mm on the UH front of the StuG III/F as you directly state? Also, I'd be willing to bet the armor quality on the Tiger 1 is better than what that StuG has.
Regards,
John Kettler
Sorry my bad, I should have been more clear,
I mean at 500m or more, not that it couldn't penetrate at any range. Ive seen the F-34 kill Pz4 from SH and LH in game from 200m or so. Ive seen flukes farther than that, but reliably.
Sorry for that confusion, I thought the debate was for 500m distance, not any range. Of course F-34 could do it at 100, or even 200m. MAYBE even 500m, but not reliably I think.
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shift8,
The issues raised have been extensively looked into: from firing trials by both the Germans and the Russians, penetration calculations and combat experience. You can learn a great deal from reading the thread, which gets into the arcana of test targets, test target composition and hardness, penetration criteria, armor quality and much more. Back when JasonC was holding forth in fine fashion, I'm pretty sure he didn't have the advantage of the grog fest that is Archive Awareness. Here, for example, is a post which shows original Russian penetration test data for a whole series of guns. The comments after the post go into considerable detail not discussed in the post proper. Russian firing trials: T-34's F-34 gun vs every German tank type from Czech 38-T through Panzer IV. Full details available from Peter Samsonov, whose site it is.
Let's do some spot comparisons, shall we? T-34 M41 (cast turret) (F-34 gun, L/42) vs Panzer IV/E (inferred based on other tanks tested, we're talking a Barbarossa period version, but with 20 mm add-on side plate, thus "E" model). From the CMBB Strategy Guide, page 2/31, the penetration numbers in mm are as follows:
100 meters (69)
500 meters (71) Delta may be shatter gap related, since Germans are using face hardened armor.
1000 meters (62)
Panzer IV/E, ibid. , page 2-47, Upper Hull is 30 + 30, giving an apparent 60 mm protection. I say apparent because there are other factors at work here, depending on what's fired, where and how it hits, etc. Spaced armor isn't the same as monobloc armor. Even so, it's apparent the T-34's gun marginally penetrates the Panzer IV/E's frontal Upper Hull at 1000 meters. This fits the Russian test results in which at 800 meters (max range tested) the AP shell goes smashing through.
(Fair Use)
The PzIV is tested next. Its front armour is penetrated at 500 meters (entrance diameter 90 mm, exit diameter 100 mm). From 800 meters, another penetration. The front armour plate is shattered into two pieces. Another shot from 800 meters penetrates the front. The testers switch to firing at the side at 800 meters.
Now, let's look at the Sturmgeschutz III/F, with its 50 + 30 Upper Hull. A straightforward comparison of that armor with the F-34's CMBB penetration figures indicates getting through the armor is hopeless--at any range from zero out. Really?
The German test data shows the F-34 can defeat the StuG's thick frontal armor as follows:
76.2mm. L.42.5 F-34.
APHE (propellant black powder with nitro-celuose primer).
81mm. at 100 metres.
69mm. at 500 metres.
61mm. at 1,000 metres.
HVAP "Arrowhead" (propellant nitro acetone based).
104mm. at 100 metres.
94mm. at 500 metres.
85mm. at 1,000 metres.
The same F-34 gun can defeat a dead-on Tiger 1's frontal armor at 100 meters. This being the case, how is it, then, that a Tiger 1's Upper Hull (110 mm @ 9 deg slope--calculator used below gave erroneous results on effective thickness) can be defeated by the F-34, presumably firing AP shell, at 100 meters based on Russian firing tests conducted after Kursk, else Ferdinand wouldn't be in list, but in CMBB, 80 mm of armor on the StuG III/F can't be defeated at zero range? What's wrong with this picture?
The above is but one example of why there are long threads talking about the undermodeling of Russian guns. In game terms, the StuG III/F is a super AFV vs the T-34/76s (immune vs it frontally at all ranges), but it can kill the T-34/76 M41 (effective Upper Hull armor is 52 mm--45 mm @ 60 deg) out to 2000 meters.
KwK L/43 penetration
100 meters (128)
500 meters (117)
1000 meters (104)
2000 meters (82)
Still think CMBB is right in how it models Russian gun performance vs German AFVs?
Regards,
John Kettler
For starters, I dont know what version of CMBB you have....but those penetration values arent whats given in game.
The T-34 has the following values for the 76:
APC from 100, 500, 1000m: 93, 73, 63.
APCR: 133, 95, 62.
Actual Russian numbers for the APC round: 88, 69, 60. (http://amizaur.prv.pl/www.wargamer.org/GvA/weapons/soviet_guns5.html)
APCR: 500m 90mm, 1000m 60mm.
With APCR, it would certainly make it though at 500m or so-----and it does just that in game. So I dont know what the deal is.
76mm APC did not penetrate the 80mm of armor on Stugs or Pz4s: in game, theoretically, or IRL. It doesnt even come close. Even the German figure you posted completely agree with that.
Also, you info on the Tiger is wrong. The Front Upper Hull, by which I think you mean superstructure: is 100mm thick, 100.9mm if you want to nitpick and add in the slope.
To Boot, the chart you lined to shows a maximum penetration at 100m of just over 90mm. Basically in agreement with what I just posted. Totally in inadequate to make it thought the Tigers Hull.
CMBB and RT do the armor just fine. The Both the chart you sent, the games values, and the data I posted all agree that the 80mm is too much for the 76mm in T-34 except at 100m or less.
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Here's an image of what a partial penetration may look,like!
It's captioned as being a 17pdr AP shell that hit a Tiger's front glacis.
Indeed, I have seen this image. Question is, how does CMBN view it.
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shift8,
If you think BFC's got the armor model perfect, then you haven't played CMBB, the second CMx1 game! Jason C is the man on this stuff--along with much else--, and you will learn a great deal from what he has to say. A little digging, will, I believe, produce similar complaints on the CMRT Forum.
http://community.battlefront.com/topic/83301-is-the-t-34s-gun-really-under-modeled-in-the-game/
Regards,
John Kettler
Well I haven't read the entire thread, the the opening statement in the thread is nonsense. The 76mm ZiS would have been very hard pressed to get though the 80mm on a Stug, even at 500m---in fact youd need to be at least 200m or less, given that the 0 degree penetration for the 76mm in the T-34 was only 69mm at NORMAL. and 88mm at 100m.
Also, I disagree that the CMBB has any serious issues. The AP simulation in that games is one the the best ever done.
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Disregard.
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Maybe it's just flavour text, with no real difference. Would be easy to program in to give people the impression that amazing simulation is going on under the hood.
This isnt the case. Even since CMx1 the AP simulation has been near perfect. Virtually everything is taken into account in CMx2 especially.
This is why the CM series of games is basically the only thing out there will accurate WW2 tank combat.
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At first I always thought that a partial penetration was as defined in certain US Army tests: A bulge on the inside armor but no break in the armor.
In CMx1 this made sense to me, as tanks rarly went down due to PP, but might bail if they were rookie crews.
In CMx2, PP seems to kill tanks about as often as it does nothing, making me think it might be alot more than just a bulge in the armor, as I seriously doubt the abillity of such a bulge to cause the tank to explode or catch fire......as can happen in CMx2.
It makes me wonder if the PP in CMx2 if not just a bulge, but perhaps varying states of "less than complete" clearance of the projectile through the armor. For example, half the shell might get stuck in the armor, and the rest breaks off and fly though. Or in other cases perhaps only a chink of the projectile makes it in. In any case, the more testing I do the less likely it seems that it is just a bulge in the inside armor, as and damage caused by that would seem more in line with spalling.
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BFC know. They won't tell. The game isn't amenable to the analysis you're trying to draw, and for all practical purposes the difference is irrelevant. It's flavour. There are so many other variables that the difference between partial and spalling or full is just, effectively, Charles showing off his programming skills: he can design a system that draws the distinction more finely than any other game, even if it's largely, practically irrelevant.
I only want to know out of curiosity. And Im not so sure the distinction is as small as you think. Ive seen many a tank downed by a PP, which is one of the main reasons I want to know what it entails. I haven't seen a tank knocked out by spalling yet--not that it cant happen...but clearly the PP is a more significant effect. But oh well. If nobody is saying oh well.
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Not really it doesn't. Since you would have to run hundreds or thousands of instances to be able to tell the difference in practical terms between "spalling" and "partial pen" hits. Are you going to do that?
That doesn't even make sense, much less bear any relevance to the question. When the game was designed, specific parameters had to have defined what a "partial penetration" was. So there IS a clear definition, and Im posting here to find out if the devs or someone else has ever known or put out what that was.
Knowing the difference between a Penetration and a partial penetration as it was defined by the dev's makes a huge difference with regard to understanding the game and its mechanics. Is a PP part of the projectile making it through but not all? Or perhaps the shell is lodged in the armor and sticking out? Or perhaps it just means a large bulge in the interior without a crack or hole in the plate? Or maybe its all or none of these things at the same time. It matters because it helps to know how effective a round is being when it PP's, and if the game is being accurate.
If noone knows the difference then oh well, but you needn't walk in here and disregard the question just because you dont have the info to answer it. Your not going to sit here and have the gall to tell me what does or does not matter to me, or what should matter to me. That is my prerogative, not yours. Dont have the answer or dont personally care? Fine, but dont try to push it on me.
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It matters to me since it tells me how the penetration mechanics in the game work.
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M-61A1 penetrates the same. M72 does better vs RHA.
M72 could penetrate 92mm at normal and could be able to make it through 80mm at 24 degrees.
M61 would make it though 80mm RHA at 9 degrees.
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So what exactly does this mean in CM? I originally thought that it might just be round making it part of the way through the armor....but that would apply to just about any hit that doesn't penetrate.
So in a PP does some of the round make it through?
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I don't remember where I read that and don't have time at the moment to search for it. As I said, there could have been some usage in 1944 but it would have been rare. M61 was a replacement for M72 so it's unlikely M72 was still being issued.
M61A1 penetration of RHA at 500 meters is 81mm.
Sorry but that doesn't solve the issue. 81mm would make penetration of the Superstructure on the Pz4 or Side Superstructure on the Tiger extremely difficult. Any round impacting at a angle of greater than 9 degrees offset wouldnt make it though, and thats not accounting for the fact that no two rounds go down range exactly the same, hence the penetration tables being averages of penetration within certain criteria. If 81mm was enough, then we'd be seeing Sherman 76mm's KOing Tigers from 1200m with straight shots....and we dont see that in game....or from historical reference FTM.
WO185/175 claimed 94mm of penetration for the M-61 round and 88mm for the M-72 at 500m, granting alot more room for error especially with a little obliquity. Perhaps the penetration tests the Americans conducted were on the low side?
Then again, the same rounds tested by the Americans in the M2 gun had precisely the same relationship between them regarding penetration. M-72 being better vs RHA.
I cannot find any evidence from a source that isn't random chatter on a forum that M72 AP fell out of use, and I have found at least on picture of a Sherman crewman in September of 1944 carrying the M-72 round. If you don't have time to look for the source then that is your prerogative, but until I see something substantial I see no reason to assume M-72 AP wasn't being used in large numbers right along side M-61 and M-61A1 right up to the end of the war. It would seem silly to get rid of a round that was completely superior to the M-61 against the most common type of armor found on German tanks. Since M72 AP could penetration 92mm of RHA at 500m, and 84mm at 750m, this seems much more in line with the performance of the gun in ALL of the CM games.
Either that or the M-61 historically penetrated alot more armor than the official American testing claimed. WO 185/175 being evidence for that.
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What is the sources on M72 not being used in 44? So far all I can find on the internet is heresay on other forums but no sources.
Also, if M72 wasnt being used, then why does just about everyone agree the performance on the 75mm gun? Regarding the Pz4 Front or Tiger side, every combat mission allows for penetrations around 500m, as well as many other games etc. It appears to me as though only M72 would do the job.
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This is just a curiosity I am hoping someone here can answer.
So in all the combat mission games the Sherman 75mm can penetrate the 80mm hull on the Pz4 from 400-600m fairly reliably. I have no problem with this whatsoever.
What I am curious about is the relationship between the M61, M61A1, and M72 rounds. In the data from hunnicutts book, the M72 seems to do better vs RHA, but in the British tests shown in WO 185/175, the M61 out of the M3 does better than the 72 vs RHA.
Now, several websites I have seen claim the M61 is capable of the 3.7inches of penetration or 94mm vs RHA, and that seems to be very much in agreement with the 92mm often seen quoted for penetration at normal in other places. However, I saw a photo of a book recently on some forum showing 81mm at 0 for the M61 and the 92mm for the 72 at 0.
Basically, what I want to know is this: is the 92-94mm at normal for the M72 or M61? In addition, was the M72 still being used in 1944 in NW Europe? I have searched all over and have found scant evidence for this. The best thing I have found so far is one picture of a M72 being held by a crew in italy in 1944.
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Well then I vote after Bulge they make Combat Mission Operation Unthinkable!
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Why is this? Is it done on purpose?
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Need some help with this if anyone can!
I want to import units from CMBN to CMRT. or Vise Versa.
Any Ideas on how to do this?
Tiger Armor Issue
in Combat Mission Battle for Normandy
Posted
I am refering to the American long 76, not the Russian short one.